package main

import "fmt"

func main() {
	// 只有len 没有cap
	var m1 map[int]string
	fmt.Println("m1= ", m1)
	fmt.Println("len = ", len(m1))
	//fmt.Println("cap = ", cap(m1))

	m2 := make(map[int]string, 10)
	fmt.Println("m2= ", m2)

	fmt.Println(m1 == nil) // true
	fmt.Println(m2 == nil) // false

	countryCapitalMap := map[string]string{"France": "Paris", "Italy": "Rome", "Japan": "Tokyo", "India": "New delhi"}

	fmt.Println(countryCapitalMap)
	fmt.Println("key France: ", countryCapitalMap["France"])
	fmt.Println("key france: ", countryCapitalMap["france"])
	fmt.Println("key france is ''? ", countryCapitalMap["france"] == "")
}
